Setting optimization options for PNG-24 format

PNG-24 format is suitable for compressing continuous-tone images. However, PNG-24 files are often much larger than JPEG files of the same image. PNG-24 format is recommended only when working with a continuous-tone image that includes multilevel transparency. (See About PNG-24 format.)

To optimize an image in PNG-24 format:

1 Choose PNG-24 for the optimization format.

2 Select Interlaced to create an image that displays low-resolution versions in a browser while the full image file is downloading. Interlacing can make downloading time seem shorter, and assures viewers that downloading is in progress.

3 If the image contains transparency, select Transparency to preserve transparent pixels as transparent; deselect Transparency to fill fully and partially transparent pixels with the Matte color. (See Making transparent and matted images.)

Optimizing Images for the Web > Optimizing images > Setting optimization options for PNG-24 format